Luminous-tube sign



Aug. 13, 1929. w. F. HENDRY 2 4 LUMINOUS TUBE SIGN Filed Dec. 4, 1926 2sheets-su ar 1 Aug. 13, 1929.

w. F. HENDRY LUMINOUS TUBE SIGN Filed Dec. 4, 1926 2 Sheets-Sheet 2 Z myi mm I l q F ..IFILIIHIITILIIITI:

my "my FOR SALE //7ven/0r W 1 WW by A Patented Aug. 13, 1929.

UNITED STATES PATENT OFFICE.

WILLIAM E. HENDBY, OF OSSINING. NEW YORK, ASSIGNOB T MANHATTAN ELEC-TRICAL SUPPLY COMPANY, CHICK, A CORPORATION OF MASSACHUSETTS,

LUMINOUS-TUBE SIGN.

. .Application filed December 4, 1926. Serial No. 152,629.

This invention relates to luminous tube signs and more particularly toelectric'discharge tubes adapted for display or advertising use.

It is the object of the present invention to provide a neon or othergas-filled discharge tube of transparent or translucent material,

and paint or otherwise apply letters or other symbols to the outsidethereof.

With this object in view a discharge tube having a substantially flatsurface is provided with the usual electrodes to create a dischargeacross a space which is preferably filled with a rare gas such as neon.Owing to this discharge the gaseous filling of the tube will be renderedluminous. The luminous discharge takes place between the electrodes anddoes not entirely fill the envelope. This is particularly noticeable ifa tube of large dlameter is used, in which case the discharge appears asa thin stream going from one electrode to the other.

In accordance with the present invention means are provided forspreading the lu minous discharge over a large area. I accomplish thisby constructing the vessel in the form of a flattened envelope, one ofthe sides of which is covered with tinfoil or other suitable metallicbacking. The tube is preferably provided with external electrodes, oneof which is connected with the tinfoil backing. lVhen current is appliedto the two external electrodes the exposed fiat side of the tube willappear to be entirely illuminated.

The invention will be more clearly understood from the followingdetailed description of two embodiments of the invention. In' thedrawings Fig. 1 is a front view 40 and Fi 2 a sectional view of oneembodiment; Tig. 3 illustrates a second embodiment; and Fig. 4 a signassembly.

The glass or other transparent or translucent vessel 1 is flattened andhas a substantially. oval cross-section. The vessel opens into twochambers 2 and 3 which are surrounded by external metallic electrodes 4:and 5 at which current may be applied to the tube in the well-knownmanner. The chamber 2 has also a small internal electrode 6 which'isconnected with the external electrode 4 in the manner and for thepurpose fully set forth in my copending application Serial No. 147,298,filed Novemher 9, 1926. A discharge will take place from electrodes 4and 6 to electrode 5, the width of which would be normally aboutone-third of that of tube 1. In order to spread this dischargethroughout the width of tube 1, one side/of the latter is covered by anextension of electrode 4. In the present case this is accomplished byplacing tinfoil 7- over theone face of the tube 1, the tinfoil extendingfrom the electrode 4 to the connection between chamber 3 and tube 1. Thetinfoil will spread the luminous gas throughout the tube 1, whereby theexposed front wall of the tube will appear to be entirely illuminated.This effect is heightened'by black paint applied to the tinfoil backing7 and the reflecting quality of the tinfoil. I

The exposed face of tube 1 may be used as a background foradvertisements or other signs. lVords or pictures may be painted,stencilled, or otherwise applied on the outside of the glass vessel andwill appear entirely illuminated when current is applied to electrodes 4and 5.

Since tubes of the present construction run cold, the symbols orcharacters painted on the tube need not be protected against heat.

Fig. 3 illustrates a modified form of the tube embodying the presentinvention. In this figure the envelope 1 is not provided with narrownecks leading to chambers 2 and 3 of Fig. 1, but is of substantiallyuniform'width throughout. Here also the envelope is oval incross-section and presents a substantially fiat surface for theapplication of advertising matter. A further difference between theembodiment illustrated in this figure and the one previously describedconsists in not extending the metallic backing 7 all the way to theexternal electrode 4. The metallic backing is connected with the currentsupply circuit as a third external electrode and operates as in theprevious case to fill the entire cross-section of the tube with light ofeven density.

The circuit illustrated in this figure comprises an alternating currentsource which is associated through a transformer 10 with two inductioncoils 11 and 12 of a well-known type. The induction coils in turn areconnected with the external electrodes 4 and 5 and the grounded ends ofthe coils are connected through a conductor 13 with the metallic backing7.

Tubes like the ones illustrated in Figs. 1 and 3 may be mounted insuitable holders such as the one illustrated in Fig. 4. A cabinet 15carries on its rear panel vertical stri s of insulating material 16, 17and 18; 6n strips 16 and 18 clips such as 19 are mounted which areadapted to hold the tubes 1 at their ends, and through these clipsconnections are established with the induction coils 11 and 12 mountedin the base 20 of the cabinet. The central insulating strip 17 carries abus bar 21 which is adapted to contact with the metallic backing 7 ofthe tubes. If tubes like the one shown in Fig. 1 are used, the centralstrip 17 is .left out. The tubes are held in place by means of hingeddoors 22 mounted on the cabinet. The height of the cabinet will, ofcourse, depend on the number of tubes it is desired to mount therein.

What I claim is:

1. A gaseous discharge tube having a flattened wall on the outside ofwhich symbols are applied, and means for spreading the gaseous dischargein said tube to fill substantially the entire cross-section thereof withlight of even density.

2. A gaseous discharge tube having an elongated cross-section at leastone wall of which presents a flattened surface for the application ofsymbols, and means for spreading the gaseous discharge in said tube tofill substantially the entire cross-section thereof with light of evendensity.

3. In a gaseous tube advertising sign, an envelope containing a gaseousatmosphere, said envelope being elongated and having one substantiallyflat surface, an external electrode at each end of said envelope wherebyan electric current can be passed through said atmosphere, an externalelectrode covering a major part of the envelope except said flatsurface, whereby the discharge is caused to spread out and fillsubstantially the entire cross-section of the envelope with light ofeven density, and means applied to the flat surface of the envelopewhereby a symbol is illuminated with the tube in operation.

4. In a gaseous tube advertising sign, an envelope containing a gaseousatmosphere, said envelope being elongated and having one substantiallyflat surface, an external electrode at each end of said envelope whereby an electric current can be passed through said atmosphere, anexternal electrode covering a major part of the envelope except saidflat surface, whereby the discharge is caused to spread out and fillsubstantially the entire cross-section of the envelope with light ofeven density, means applied to the flat surface of the envelope wherebya symbol is illuminated with the tube in operation-,and an alternatingcurrent source connected with all the three external electrodes.

In testimony whereof, I have signed my name to this specification this3rd day of December, 1926.

WILLIAM F. HENDRY.

